/*
 * Copyright 2011 The IEC61850bean Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */
package com.beanit.iec61850bean;

import com.beanit.asn1bean.ber.types.BerBitString;
import com.beanit.iec61850bean.internal.HexString;
import com.beanit.iec61850bean.internal.mms.asn1.Data;
import com.beanit.iec61850bean.internal.mms.asn1.Integer32;
import com.beanit.iec61850bean.internal.mms.asn1.TypeDescription;

public abstract class BdaBitString extends BasicDataAttribute {

    final int maxNumBits;
    volatile byte[] value;

    protected BdaBitString(
            ObjectReference objectReference,
            Fc fc,
            String sAddr,
            int maxNumBits,
            boolean dchg,
            boolean dupd) {
        super(objectReference, fc, sAddr, dchg, dupd);
        this.maxNumBits = maxNumBits;
    }

    public byte[] getValue() {
        return value;
    }

    public void setValue(byte[] value) {
        if (value.length != ((maxNumBits - 1) / 8 + 1)) {
            throw new IllegalArgumentException("value does not have correct length.");
        }
        this.value = value;
    }

    @Override
    public void setValueFrom(BasicDataAttribute bda) {
        byte[] srcValue = ((BdaBitString) bda).getValue();
        if (value.length != srcValue.length) {
            value = new byte[srcValue.length];
        }
        System.arraycopy(srcValue, 0, value, 0, srcValue.length);
    }

    public int getMaxNumBits() {
        return maxNumBits;
    }

    /**
     * Initializes BIT_STRING with all zeros
     */
    @Override
    public void setDefault() {
        value = new byte[(maxNumBits - 1) / 8 + 1];
    }

    @Override
    Data getMmsDataObj() {
        Data data = new Data();
        data.setBitString(new BerBitString(value, maxNumBits));
        return data;
    }

    @Override
    void setValueFromMmsDataObj(Data data) throws ServiceError {
        if (data.getBitString() == null) {
            throw new ServiceError(ServiceError.TYPE_CONFLICT, "expected type: bit_string");
        }
        if (data.getBitString().numBits > maxNumBits) {
            throw new ServiceError(
                    ServiceError.TYPE_CONFLICT,
                    objectReference
                            + ": bit_string is bigger than type's size: "
                            + data.getBitString().numBits
                            + ">"
                            + maxNumBits);
        }
        value = data.getBitString().value;
    }

    @Override
    TypeDescription getMmsTypeSpec() {
        TypeDescription typeDescription = new TypeDescription();
        typeDescription.setBitString(new Integer32(maxNumBits * -1));
        return typeDescription;
    }

    @Override
    public String toString() {
        return getReference().toString() + ": " + HexString.fromBytes(value);
    }

    @Override
    public String getValueString() {
        return HexString.fromBytes(value);
    }
}
